Allow keystone endpoint_type interpolation for reclass models

- Add 'endpoint_type' identity parameter
- Set 'endpoint_type: internalURL' as a default parameter for
  'service' reclass model (/metadata/)

Change-Id: I9626989e2e13e6acd2f83b020709913abc841da3
diff --git a/metadata/service/server/cluster.yml b/metadata/service/server/cluster.yml
index c718ef1..d0e4076 100644
--- a/metadata/service/server/cluster.yml
+++ b/metadata/service/server/cluster.yml
@@ -6,6 +6,7 @@
   _param:
     horizon_version: kilo
     horizon_api_version: 3
+    horizon_identity_endpoint_type: internalURL
   horizon:
     server:
       enabled: true
@@ -33,6 +34,7 @@
         host: ${_param:cluster_vip_address}
         port: 5000
         api_version: 2
+        endpoint_type: ${_param:horizon_identity_endpoint_type}
   haproxy:
     proxy:
       listens: